The app will alert you when the sensor battery is low. The sensor uses a CR2032 lithium coin cell battery. You can check the battery level for each of your sensors in the app under Devices. A battery should last two years or more depending on use.
To change a Temperature & Humidity Sensor battery:
- Pry up the cover to find the battery.
- Slide it out and slide in the new battery with the positive (+) side face up.
Replace the cover in the original orientation. It should snap in place.